PC versus GPS timing

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Joined: 2011/10/22 - 03:39
PC versus GPS timing

I have a question about the timing between the time data that comes off a GPS receiver (UTC) and WSPR software.
My PC says my timing is early but I think it is right on schedule.

I spent a couple of hours in the shack this afternoon and build up a WSPR transmitter - just TWO chips to RF.
- using only a microcontroller to generate the data for a DDS- IE I produce WSPR direct on frequency from the DDS, passing through an output filter and amplifier 100mW. No transceiver, no PC. Just two chips. Generates WSPR from DC to 150 MHz anywhere.

Now, trouble is, my computer receiving it on a rig says the timing is "-2.0". I gather is means that the WSPR transmitter is 2 seconds early.. I think....

However, I am starting the sequence at exactly 1 second past the top of the minute- and it is timed against the GPS.
It should be bang-on.

Now, if users are only using the PC software, as I expect everyone is, the delays would probably be all the same, and no one would notice this behaviour.

any ideas ?

73, glen english VK1XX QF43